Nicky Hilton Rothschild rocks her dresses repeatedly.

A proponent of sustainability in fashion, she keeps her faves in steady rotation.

“I’m constantly mixing and matching and re-wearing old pieces,” the businesswoman told The Post at the Oscar de la Renta show during New York Fashion Week. “And I inherited a lot of beautiful vintage from my mother. You can reinvent it a bit with accessories, or belt it.”

“I was actually talking today with Diane von Furstenberg about how I have had her wrap dresses in my wardrobe for 20 years,” continued the 36-year-old mother of two. “I wore my DVF wrap dress to an Oscar party 15 years ago, I wore it to Diane’s show a few seasons ago and then wore it again to the Statue of Liberty Museum opening. It’s such a timeless, classic silhouette.”

Hilton said she wants to introduce sustainable footwear to French Sole collab. “I’ve been looking at all the eco-friendly materials — all these different types of soles made out of recycled plastic bottles.”

And could she shop sustainably in the closet of her sister, Paris?

“We don’t really have a very similar style,” said Hilton Rothschild. “She likes pink!”